Clinical Report: Burst Wave Lithotripsy for Noninvasive Urinary Stone Fragmentation
Overview
Burst wave lithotripsy (BWL) is an emerging ultrasound-based technology offering effective, noninvasive fragmentation of urinary stones without anesthesia. Clinical and experimental studies demonstrate BWL’s ability to produce controlled stone fragments with minimal cavitation and tissue injury, potentially improving patient comfort and treatment outcomes compared to shock wave lithotripsy (SWL).
Background
Urolithiasis affects approximately 10% of the global population and is commonly treated with shock wave lithotripsy or endoscopic methods. SWL uses high-pressure single-cycle pulses at low frequency but often requires anesthesia and can cause cavitation-related tissue damage. BWL utilizes multi-cycle focused ultrasound bursts at lower pressures, minimizing cavitation and enabling treatment on awake patients. The system integrates real-time ultrasound imaging for precise stone targeting and monitoring during therapy.
Data Highlights
Parameter
Findings
Ultrasound frequency
Higher frequencies (800 kHz) produce smaller fragments (<1 mm); lower frequencies (170 kHz) produce larger fragments (3–4 mm)
Fragmentation efficacy
Up to 87% mass reduction to submillimeter dust in 10 min for small stones (1–3 mm); 89% fragmentation of human stones within 30 min
Stone size treated
Effective fragmentation of stones 1–7 mm in preclinical models
Fragment size post-treatment
At least 50% of stones reduced to <2 mm fragments; 100% reduced to <4 mm fragments in porcine models
Pressure amplitude
Up to 6.5 MPa improves fragmentation while minimizing tissue damage
Key Findings
BWL uses multi-cycle sinusoidal ultrasound bursts to generate elastic standing waves within stones, causing controlled fragmentation.
BWL minimizes cavitation compared to SWL, reducing tissue injury and eliminating the need for anesthesia or sedation.
Real-time ultrasound imaging enables continuous monitoring and precise targeting during BWL treatment.
Preclinical studies show effective fragmentation of human kidney stones implanted in animal models with significant reduction in stone size.
Ultrasonic propulsion technology integrated with BWL allows noninvasive repositioning of stones under ultrasound guidance.
Clinical Implications
BWL offers a promising noninvasive alternative to SWL for urinary stone management, potentially improving patient comfort by avoiding anesthesia and reducing complications related to cavitation. Its ability to produce smaller, controlled fragments may facilitate spontaneous stone passage and reduce retreatment rates. Real-time imaging guidance enhances treatment precision and safety, making BWL suitable for diverse clinical settings.
Conclusion
Burst wave lithotripsy represents a transformative advancement in urolithiasis treatment, combining effective stone fragmentation with improved patient tolerability and safety. Ongoing clinical validation may establish BWL as a preferred modality for managing urinary stones.
References
Maxwell et al. 2015 -- Controlled Fragmentation of Urinary Stones Using Burst Wave Lithotripsy
Moghimnezhad et al. 2021 -- Efficacy of Burst Wave Lithotripsy for Small Urinary Stones
by Steffi Kar Kei Yuen, Vineet Gauhar, Chu Ann Chai, Connor M. Forbes, Victor K. F. Wong, Ryan F. Paterson, Ivan Ching Ho Ko, Joseph Li, Daniele Castellani, Ben H. Chew
